Myth: return to battery harder on gun?

[dyl]

Hi all. Another quick myth I'm hoping someone can refute
.
I am familiar with most of the basic principles behind the mechanics of the semi auto pistol. I thought I was, at least, until I heard this:

(No offense if whoever posted this reads this, I'm just confused)
The poster stated: the slide returning back to battery is harder on the gun than when the slide is propelled rearward and impacts the locking block or whatever stops the slide. Therefore a stronger recoil spring will consistently slam the slide forward with more force and accelerate wear on the handgun.

What do you think? Personally I'm still not convinced...

 

[RickB]

Looked at from the other direction, I don't buy into the theory that guns with stock springs, shooting ammo of normal power, are suffering "battering" when the slide/barrel come to a stop on the recoil stroke; that's how the gun was designed to operate.
Now, if you increase the strength of the recoil spring, you are lessening the impact that the gun is designed to endure, but you are increasing the speed/energy with which the barrel/slide/locking device slam closed, in excess of what the gun was designed to do. Is the "extra wear" measurable? The gun will go only 150,000 rounds instead of 155,000?

 

[Aguila Blanca]

The poster stated: the slide returning back to battery is harder on the gun than when the slide is propelled rearward and impacts the locking block or whatever stops the slide. Therefore a stronger recoil spring will consistently slam the slide forward with more force and accelerate wear on the handgun.

True ... at least, in regard to 1911s (which are the only semi-autos I'm qualified to blather about).

 

[dyl]

So in 1911's, a stronger recoil spring (I'm assuming in response to a heavier load/charge) is more of a detriment than keeping the same spring and letting the slide reciprocate with more force? I might have misunderstood you.

If the slide slams forwards with more force with a stronger spring, are we at least reducing impact in the rearward travel of the slide as a benefit? Otherwise why bother replacing recoil springs?

 

[Powderman]

The return to battery issue with 1911's primarily concerns the sear/hammer relationship.

Slide velocity is within normal parameters when the slide is loading a round. The slide's velocity is lessened when feeding a cartridge. If the slide is dropped on an empty chamber, the hammer "bounces", with the hammer hooks actually peening the sear nose. Too much of this, and the sear nose will break. A 1911 suddenly going full auto with no warning is no joke.

Don't ask me how I know......but I have a nice scar on the web of my shooting hand as a souvenir.

 

[JohnKSa]

Look at it this way. You have a double-headed hammer and you swing it both ways. You hit a rock on the backswing and then you hit a second rock on the forward swing.

If you make your forward swing more energetic, it's harder on the rock in front of you and harder on your hammer. If you make your backswing more energetic, it's harder on the rock behind you and again, it's harder on your hammer.

Now, if you make your backswing lighter at the cost of making your forward swing more energetic, the rock behind you may thank you, but the rock in front of you won't be happy about that. And the hammer is still taking about the same beating, but more on the forward end than on the back end now

Now, let's turn the hammer into a slide on an autopistol, and let's make recoil the backswing and the return to battery, powered by the recoil spring, the forward swing. The rock in front is whatever stops the slide when the gun goes into battery, and the rock in back is whatever stops the slide when it reaches the end of rearward travel.

Let's say, for the sake of argument, that a stronger recoil spring actually makes the backswing/recoil less damaging.

So that's a benefit to the part of the gun that stops the slide when it's moving backwards, and maybe the slide takes less of a jolt when it is stopped on the backswing.

But the stronger spring now drives the slide forward more energetically. That means it takes a harder jolt when it stops in battery, and it also means that whatever stops it on the front stroke is taking more of a pounding.

So, did you actually help yourself?

Maybe, but you didn't get anything for free. Anything you gained by lightening the backswing, you paid back in a more energetic forward swing. It's anybody's guess as to whether the payoff was worth the cost.

 

[Lost Sheep]

And then there is the effect of putting in a recoil pad (the little 1/8" thick plastic thing that sacrifices itself to protect the rearward "rock" and you should replace every few thousand rounds in order to protect your frame during its (hopefully infinite) lifetime.

Lost Sheep

 

[1911Tuner]

re:

The return to battery issue with 1911's primarily concerns the sear/hammer relationship.

That's a myth, along with the "Hammer Bounce" theory that I see repeated a lot.

The concern is with the lower barrel lug feet, and...to a lesser extent...the slidestop crosspin holes in the frame.

Remove the barrel and install the slidestop pin through the link. Swing the link and pin to the in-battery position...and look at the relationship. Those tiny lug feet are ultimately what brings the slide and barrel to a stop. The forces involved are shearing forces, while in the other direction...they're compression forces on the slide and frame abutments.

I've seen slidestop pin holes elongated and I've seen LW Commander frames with vertical cracks in the bottoms of the holes. I've seen lower lug feet deformed to the rear and a few that were broken clean off.

On "Hammer Bounce"...

The hammer doesn't bounce. The trigger does, and even that's misleading because the trigger actually stands still when the gun is violently jerked forward. The disconnect nudges the trigger and rolls the sear away from the hammer hooks. The hammer falls, and the sear immediately resets and the half-cock grabs the sear. Finely honed sear crowns can be damaged, ruining a careful trigger job. Many smiths work to prevent this in the case of hammer followdown by removing all but the center section of the half-cock notch so that the impact is absorbed by the portion of the sear that doesn't affect the hammer hook to sear interface.

It's not a concern with long, undersquare, or "captive" ordnance spec hammer hooks and unaltered sears.

More likely to happen with a heavy steel trigger and with short, square hammer hooks and heavy breakaway angles on the backside of the sear crown, which is the reason for recent, low-mass/lightweight triggers.

Back in the day when all the AMU armorers had to work with was steel triggers, the common practice was to hold the trigger rearward when releasing the slide to get the disconnect out of the equation.

Many people consider this to be unsafe, but as long as correct procedure is observed, it's not. The function is the same as it is when firing the gun. The problem comes when it's attempted in a hurry, and instead of "Pull trigger/Drop slide" it becomes "Drop slide/Pull trigger" before the pistol is pointed downrange.

 

[dyl]

Wow. Thank you for the thought put into your responses. I have not yet explored the 1911 world so while I can visualize the sear/hammer relationship in traditional Da/SA semi autos I do know 1911's have parts that I have yet to understand. Especially that strange piece with several finger-like projections.

If I have the physics correct, a way to make a semi auto pistol take less "battering" with regard to slide reciprocation would be to: reload a lighter load which would lessen rearward force, install a lighter recoil spring just strong enough to make up the difference, and that would allow for a lighter return to battery.

Not that I currently have the money to order a bunch of recoil springs for something that may be a non-issue.

 

[HiBC]

For context:

Using standard pressure levels and original springs,its all in the balance of the original design.

Play +P+ or 460 Roland,etc,with the stock springs steel will smack steel on the rear stroke.

OK.we'll stuff a 24 lb spring in there.Yeah,that works.The spring is now in balance with the recoil stroke.

But now you have a 24 lb vs 18 lb spring throwing the slide forward,with no other changes.

As 1911 Tuner explained,hello slide stop pin and the holes in the frame,etc.

 

[1911Tuner]

Parts is Parts

I have not yet explored the 1911 world so while I can visualize the sear/hammer relationship in traditional Da/SA semi autos I do know 1911's have parts that I have yet to understand.

I think the part you're referring to is the sear spring, though it powers more than just the sear.

The trigger stirrup never touches the sear. It bears against the disconnect, which transfers force to the sear. Thus, the disconnect is both a connector...when it's at its highest point in the frame...by bridging the gap between trigger and sear, and a disconnector...when it's at its lowest point and no longer imposed between the trigger and sear.

 

[PawPaw]

So, what would make a 1911 go full-auto? Let me expound.

Last week ago I attended my first-ever club match. Thirty years of shooting and carrying guns in a military and LE capacity and I've never joined a club. I decided last week to go see what it was all about.

First stage one of the guys gets on line and starts engaging targets. About halfway through the string, his pistol goes full-auto for five shots. After he finished the string, I asked him what he was running. "A modified 2011". I've spent a lot of time on machine gun ranges, and I know what full-auto sounds like. We started looking at timer times and it appears that he got off five rounds in about a half-second.

Some of the long-time club members told the guy that in a registered shoot, if the gun did that, he'd likely be pulled from the line, but he brushed it off, saying that it had only happened once before. I'm not convinced that the guy is running a safe pistol, but as the newby, I kept my opinion to myself.

So, to educate myself, what would make a 1911 go full-auto?

 

[mes228]

Springs

Personally, I dislike overly hard springs in pistols. It takes too much effort for these older hands to rack them. They seem to accomplish nothing to me. I have pistols King Kong would have trouble racking. I have pistols that a child could rack. I prefer easily rackable pistols. All my keeper pistols are reliable, accurate, and many have fired thousands of rounds. I see no difference in any area between hard/soft springing. I have no idea why manufacturers have, for the most part, gone to stiffer springing. As an aside, who can afford to wear out a pistol with today's ammo prices? I've practically given up recreational shooting. I now shoot only 1-2 boxes a week and that HURTS $$$$. I do not worry at all about frame battering as I've not seen it in anything I own.

 

[Aguila Blanca]

So in 1911's, a stronger recoil spring (I'm assuming in response to a heavier load/charge) is more of a detriment than keeping the same spring and letting the slide reciprocate with more force? I might have misunderstood you.

You didn't misunderstand me, but you misunderstand the operation of the pistol.

If the slide slams forwards with more force with a stronger spring, are we at least reducing impact in the rearward travel of the slide as a benefit? Otherwise why bother replacing recoil springs?

Consider how the pistol functions.

Upon firing, the slide and barrel are locked together as they begin to travel to the rear. After about a quarter of an inch, the barrel links down and they then become two unconnected parts. The rearward movement of the barrel is stopped when the underlug of the barrel contacts the VIS (Vertical Abutment Surface) inside the frame. This is a solid chunk of steel that connects both sides of the frame and extends all the way back to (and includes) the frame feed ramp. There's plenty of metal there to absorb impact.

The slide stops when the rear edge of the forward recoil spring tunnel makes contact with the flange of the recoil spring guide. The flange, in turn, is already seated against a shoulder inside the frame from which solid steel extends all the way to the back of the frame. Again, there's plenty of metal there to absorb the impact.

Now consider what happens when the recoil spring is driving the slide and barrel forward, back into battery. The slide moves forward. Along the way it strips a round from the magazine and pushes it into the chamber. Then the breechface strokes the barrel hood and starts moving the barrel with it. The barrel gets linked up, the locking lugs engage, and we now have the combined mass of the slide and barrel being impelled forward by the combined energy of the recoil from the slide bouncing off the frame (an elastic collision) plus the energy added by the recoil spring. What STOPS this forward motion/momentum?

It stops when the two little feet at the very bottom of the barrel underlug contact the cross pin of the slide stop. This has a diameter of 0.200 inches, which is a cross-sectional area of only 0.03 square inches. That's ALL that stops the slide and barrel when the pistol slams back into battery. Hitting it harder than necessary greatly increases the probability of shearing the cross pin. When that breaks, the pistol is out of action.

Calling the recoil spring a "recoil" spring is actually a misnomer. Browning referred to it as the "action" spring. Its purpose is not to absorb recoil (it absorbs only a small fraction of it anyway). It's purpose is to load the next round and to return the pistol to battery. Ideally, you want to use the weakest recoil spring that will accomplish this reliably. We replace recoil springs when they get too wimpy to reliably load a new round and return the pistol to battery.

 

[1911Tuner]

Burp

So, to educate myself, what would make a 1911 go full-auto?

First, let's explore what won't do it.

Hammer follow...even if it goes all the way to the slide...is highly unlikely to cause even a double. I'd go as far to say that it can't happen with a hammer that simply follows the slide if all is within spec.

Why?

Because the hammer is borne by the slide's center rail, the hammer's face can't reach the firing pin until the final .050 inch or so of travel, and thus can't gain the speed and momentum needed to overcome the firing pin's inertial resistance and the firing pin spring's load. Jack the slide backward a tiny bit, and look at the gap between the hammer face and the rear of the firing pin.

In order for one to burst fire, the hammer has to hold at full cock and jar off as the slide slams to battery. In a normal full-auto function, the hammer is tripped at precisely the right time. It has to work that way on a malfunctioning 1911 pistol, too.

In order for that to happen, there has to be two malfunctions. One is that the hammer must hold at full cock and be tripped...or jarred off...and the other is that the sear must fail to reset and grab the half-cock notch.

 

[James K]

You can install a heavy recoil spring, which reduces battering in one direction and increases it in the other, where the damage will be a lot greater.

You can install a buffer, which will absorb the energy of recoil rather than returning it to the slide, resulting in failures to feed.

As some smart fella once said, "There ain't no such thing as a free lunch."

Jim

 

[Ben Dover]

James K You can install a heavy recoil spring, which reduces battering in one direction and increases it in the other, where the damage will be a lot greater.

You can install a buffer, which will absorb the energy of recoil rather than returning it to the slide, resulting in failures to feed.

As some smart fella once said, "There ain't no such thing as a free lunch."

Quite so! Everythying comes at a price

I have heavier than factory recoil springs in all of my Glocks and SIG-Sauers due to my long time propensitry to practice with very heavy loads.

Even as much as I shoot, at 73, I doubt I'll loive long enugh to see any damage to my pistols! (I also enjot havinf the empties drop right at my feet)

 

[Wreck-n-Crew]

The poster stated: the slide returning back to battery is harder on the gun than when the slide is propelled rearward and impacts the locking block or whatever stops the slide. Therefore a stronger recoil spring will consistently slam the slide forward with more force and accelerate wear on the handgun.

Too strong a recoil spring causes more damage than a weak one. The more the spring pressure is increased to keep a breach closed the more damage it can cause because the pressure should be relieved more by blow back.

Not saying the gun should be built tough enough to withstand a heavier spring. Just that a heavier spring puts more pressure on the breach.

Now I don't mean chamber pressure but recoil pressure.

Think of it this way: take a 20 ounce hammer and try to drive a nail into a lightly braced 2x4. Hard to do. The same amount of pressure or force used to drive a nail into a 2x4 that is well braced has more effect.

Now remove the nail and just strike the 2x4 braced and unbraced. Which sustains more damage?

The gun with the heavier recoil spring is like bracing the 2x4 and the unbraced 2x4 is the lighter recoil spring.

The blow or force is lessened when movement of the slide is not too restricted.

 

[JohnKSa]

The more the spring pressure is increased to keep a breach closed the more damage it can cause because the pressure should be relieved more by blow back.

The recoil spring is not what keeps the breech closed in a recoil operated firearm.

The slide and barrel are locked together mechanically and remain locked together until they move sufficiently to the rear for the unlocking mechanism to separate them. By the time the unlocking mechanism separates the barrel and slide, the bullet is out of the barrel and pressure has dropped to essentially ambient pressure.

That is true whether or not a recoil spring is present since the timing is controlled nearly exclusively by conservation of momentum and the design of the locking/unlocking mechanism.

 

[Wreck-n-Crew]

The slide and barrel are locked together mechanically and remain locked together until they move sufficiently to the rear for the unlocking mechanism to separate them.

Not in several semi autos is that the case.

The only force holding closed a Cobra arms CA 380 for example are held only by the tension of the recoil springs.

As far as I know the newer tilt down barrels are mechanically locked, at least somewhat from the definition of locked means.

Many fixed barrel semi-autos don't lock. Just the force of the recoil holds them closed.